V-Moda's Crossfade M-100 headphones represent a rare experiment that suggests some of the listeners themselves are the best designers. We're about to learn whether practice matches theory now that the over-ears are shipping. Those who spend $310, slightly more than the originally promised $300, should get a black or white body, an in-line microphone remote and a set of removable shields to tailor the look. V-Moda justifies the price mostly